Liquid fabric compositions are well known to the consumer and may be divided in two types: concentrated compositions with 5% to 80% of fabric softening agents and diluted compositions with 1% to 5% of fabric softening agents. Concentrated fabric softening compositions are well appreciated by consumer. However, concentrated compositions may be expensive. This may be due to processing cost and/or material cost of the formulation. Diluted fabric softening compositions, are also known by consumer for providing a cheaper alternative to concentrated compositions without reducing the softness performance.
Consumer acceptance of such compositions is determined not only by the performance achieved with these products but the aesthetics associated therewith. Viscosity of the product is therefore an important aspect of the successful formulation of such commercial products: stable medium to medium-high viscosities being highly preferred by consumer. By medium-high viscosities is meant viscosities of 50 cps to 150 cps when the fabric softening composition is in a diluted form and viscosities of 30 cps to 90 cps when the fabric softening composition is in a concentrated form. To this end, thickeners such as compounds of the polyacrylamide, polysacharide or polyurethanes type have been widely used in such compositions. Although, these compounds are effective in providing the thickening effect, they increase the cost of the formulation without adding any other benefit to the product.
Another aesthetic point which may be of concern to the consumer is that of resulting odour of the product. To this end, products which contain a high level of perfume relative to the total amount of biodegradable fabric softening components and fatty acid components present within the composition are most preferred. However, a problem encountered with such high ratios is that of stability of the perfume, especially where the fabric softening composition contains a low amount of such actives (i.e sum of biodegradable fabric softening components and fatty acid components), especially less than 10% by weight of the composition.
Still another important aspect of successful formulation of such commercial product is that of the resulting storage stability after exposure to high temperatures.
The Applicant has now found that the use of high levels of fatty acids relative to the level of biodegradable fabric softening agents in a liquid fabric softening composition overcomes the problems.
It is therefore an object of the invention to provide a liquid fabric softening composition which has a suitable viscosity, provide excellent softening benefit and is inexpensive.
It is another object of the invention to provide at liquid fabric softening composition with effective storage stability.
It is another object of the invention to provide a liquid fabric softening composition which also contain high level of perfumes relative to the total amount of biodegradable fabric softening components and fatty acid components.